The absolute configuration of dichapetalin A, [(4 alpha,'alpha,7 alpha
,17 alpha,20S,23R,24E)-2',3',5',6'-tetrahydro- e-29-nordammara-2,11,24
-tri-eno[4,3-c]pyran-21-oic acid gamma-lactone], the major cytotoxic c
onstituent from Dichapetalum madagascariense has been established to b
e 4R,5R,7R,8R,9R,10S,13R,14S,17S,20S,23R,6'S. Copyright (C) 1996 Elsev
ier Science Ltd